Disposable blood-gas analyzer



June 14, 1960 N. B. FURLONG, JR 2,940,448

DISPOSABLE BLOOD-GAS ANALYZER Filed April 29, 1957 .1. I," I Q Fig; F1 3 Pizza/r 09: an Mayor/p! (to) ,v 19/:

INVENTOR. Nona/v E ERMA/s, JR.

. BYLU United A States Patent DISPOSABLE BLOOD-GAS ANALYZER Norman B. Furlong, Jr., 5241 Cobb Drive, Dayton, Ohio Filed Apr. 29, 1957, Ser. No. 655,922

10 Claims. (Cl. 128-276) (Granted under Title 35, US. Code (1952), sec. 265) The invention described herein may be manufactured and used by or for the United States Government for governmental purposes without payment to me of any royalty thereon.

'This invention relates to a device for providing a roughly accurate quantitative analysis of the carbon monoxide content in blood.

As a background for understanding the present invention reference is made to Handbook of Poisons by Robert H. Dreisbach, published in 1955 by Lange Medical Publications, University Medical Publishers, Los Altos, California. p

A brief summary of the invention follows indicating its nature and substance together with a statement of the object of the invention commensurate and consistent with the invention as claimed and also setting out the exact nature, the operation and the essence of the invention complete with proportions and techniques that are necessary for its use. The purpose of the invention also is stipulated. The presentation is adequate for any person who is skilled in the art and science to which the invention pertains, to use it without involving extensive experimentation. The best mode of carrying out the invention is presented by the citing of a specific operative example, inclusive of the preparation and the use of at least one example of the invention.

The object of this invention is to provide a self-contained, inexpensive, disposable device which may be rapidly used by an untrained person with simple manipulation in the making of a reasonably close approximation of aquantitative determination of the carboxy-haemoglobin in a blood sample under standard conditions, after which the device is discarded.

;The device does not replace an exact quantitative determination of carbon monoxide absorption into the blood stream, but it is adequate for providing a quick estimate in the hands of a person without skill, beyond observation and judgment in the comparison of shades of color. The device contemplated hereby includes in one unit the factors of sterilization, vein puncture, blood sampling, chemical reaction reagents to release carbon monoxide from the carboxy-haemoglobin molecule and means for making a quantitative colorimetric close determination of the carbon monoxide released from the blood sample taken from the patient.

In the accompanying drawing:

Fig. 1 is a plan view,partly in section, of a hypodermic syringe reaction chamber and a protective covering, which embody the present invention;

Fig. 2 is an enlarged sectional view of the hypodermic needle protecting and sterilizing cap shown in Fig. 1;

Fig. 3 is an elevational view of the open end of the cap shown in Fig. 2;

Fig. 4 is an enlarged sectional view of the hypodermic syringe shown in Fig. 1;

Fig. 5 is a sectional view taken along the line 5-5 of Fig. 4;

Fig. '6 is a plan view, partly in section, of a commer- 2 cially available colorimetric analyzing equipment, as applied to the assembly shown in Fig. 4; and

Fig. 7 is a quantitative carbon monoxide colorimetric chart, usable with the color band of the colorimetric tube shown in Fig. 6.

The syringe illustrated in Fig. 1 of the accompanying drawing consists of a hollow steel hyodermic needle 1 with its distal or unattached end 2 sharpened for skin and vein penetration and a reaction chamber 3 hand grasp support for the needle. The proximal or the attached end of the hollow needle 1 is mounted in sealing engage.- ment with and is supported by the extreme end of the flexible neck portion of the tough, flexible plastic reaction chamber 3. The opening through the hypodermic needle 1 is in arrested or blocked communication with the interior of the reaction chamber 3. The thin neck of an evacuated capsule 6 makes a close, axial, sealing slip fit into the neck of the reaction chamber 3 and a loose, spaced penetration into the base of the needle 1.

The reaction chamber 3 is closed and is sealed at its end remote from the needle 1 by being cemented to a cap 4, which is provided with a thin-section tear seal 5 or the like. The hollow glass capsule '6, which is exhausted to a desired degree of vacuum, has a thin walled, shear end positioned within and supported by the base of the needle 1 in the neck of the reaction chamber 3. Reagent containing, additional sealed, thin glass capsules, such as the capsule 7, may also be positioned within the chamber 3. Where desired, the capsules may be secured in place by stainless steel rings, such as the spring steel ring 8 or the like, within the chamber 3. The ring 8 is shown as a continuous wire with spaced ends. The wire is bent to a circular shape with a loop midway between its ends to receive the necked portion of the reagent containing capsule 7 within the loop. The stainless steel ring 8 is adapted for being depressed somewhat, in.

which state its unattached ends approach each other. The partly depressed, capsule supporting ring 8 is then inserted within the interior of the reaction chamber 3 to a desired position and then released so that the legs of the ring 8 bear outwardly against the inner surface of the reaction chamber 3 and retain the capsule 7 in position. The ring 8 serves the purpose of restricting the undesirable freedom of motion of the capsule it supports so that the capsule is out of contact with other occupants of the interior of the reaction chamber 3. The contents and the number of reagent containers, of which the capsule 7 may be taken as being illustrative, positioned within the reaction chamber 3 may be modified in conformity with requirements, within the contemplation of the present invention.

The capsules 6, 7, etc. within the reaction chamber 3 are made of sufiiciently thin walled glass, or similar material, so that they may be fractured or crushed by finger pressure without puncturing the walls of the reaction chamber 3. Illustratively, one of the thin walled glass capsules may contain mg. of powdered dry potassium fer'n'cyanide or a corresponding water solution thereof. A second capsule (not shown) may contain a buffer solution such as 50 mg. of citric acid and 50 mg. of sodium citrate, 10 mg. of powdered saponin, 3 drops of caprylic alcohol and illustratively 1% to 2 cc. of water. Where desired, the caprylic alcohol may be contained within the evacuated capsule 6, where it minimizes foaming of blood drawn into the capsule 6. The water, or a stable solution, may be left fpee in the reaction chamber 3 to minimize damage bygiteezing. Illustratively, thewater may be outside of the capsule 7 and the above dry reagents may be positioned within the capsule 7, Within the reaction chamber 3.

-A hypodermic needle protecting and sterilizing chain- Patented June 14, 1960 ber p'ro viding cap or sheath consists ofa plastic 'cylin-f der'or conical member, closed atone end and with its 7 opposite end open and fitting tightly over the needle supporting neck end of the reaction chamber shown in Fig. 7 l, sealing relationtherewith The cap or sheath 10 nlay be'taken as being representative. The hypodermic V accomplishing the complete extraction of ga s from the tube 18 within the free endof which the lessfilled end of needle 1 is maintained sterilized, by the antiseptic, by

which theswab 11 may be saturated. In Fig. 1 of ithe accompanying drawing, the hypodermic needle; with its ahtisepticprotective sheath 10, whichtengages the'neck of the reaction chamber 3 in sealing contact therewith,

shows the assembly in its. sealed condition and suitable forfhandling' and for storage.

"lreparatory to the use of the assembly shown in Fig. l of .the drawing the cap or sheath 10. is withdrawn fro'm:

its' s'ealing'engagement with the neck of the reaction chamber 3 and the cap 10 is tapped against the hand for causing theswab 11 to be removed therefrom. v The swab 11 may then be applied along the .hypodermic needle L'ior assuring the'sterilization thereof. The

swab 111 may thencbe applied to the skin overlying the 1 the vein for the withdrawal of a blood sample therefrom.-

' With the tip 2 of the hypodermic needle 1 within the blood filledyein, the flexible neck of the reaction chamher. 3 is deflected by the thumb, as the'fingers extend around the reaction chambers of the device. The thumb the tube 15 may be inserted sealing engagement therewith. The colorifitetrictube. IScontains, white silica gel plugged inplaceton the opposite sides of the color band 16. vThe colorimetric tube 15 base sturdy mid sect'ion, which is drawn at its opposite ends to glass of sufiiciently thinner sections to be frangible, without causing splittin up in the mid-portion of the tube. 3 f

. In use, both ends of. the colorimetric tube 15 are broken. opemthe lessfilledend is inserted into the open end of. the resilient tube '18 and the opposite end of the tube 15 is caused to-penetratethe tear seal 5 of the closure cap-4, insealing engagement therewith also. The resilience of the wall of the squeeze bulb 1 7 causes i-t to dilate against the ar nb ient atmospherewhich, upon the removal ofthe hypodermic needle protecting caplll, or the removal ofthe hypodermicneedle from a rubber or cork stopper or the like; permits. the ambient atmosphere as enter the deflection of the" flexible neck of the reaction chamber 3 is sjufiicient to rupture the thin walled seal end of the vac? tim capsule 6; thereby opening communication between the interior of the vacuum capsule 6 and the blood filled" veinthere'by causing the capsule 6 tobe filled with a predeterminedamount' of'blood, The hypodermic needle 1 is" then withdrawn from the patient and the swab 1-1 is again used to sterilize the skin wound resulting therefrom. I Q

Where desired, the'p'rot'ective cap" 10 may be replaced in sealing engagement with'the neck of the reaction chambend; thcrebyincre'asing'the' pressure upon the blood remaining within the hypodermic needle lfa'nd urgin'gth'e blood toward thereaction chamber; 3 or, if preferred;

maybecontainedwithin the 'reaction'chamber, 3, in a 7 7 .manner'may be ruptured andlpreferablyi-reducedr in particle sizeby the fingers to release c'cniipletely their contents into the interior df'therea'ction chamber?) and to assure. that. their contents will bemixed' thoroughly} withihebloodsample'within the reaction chamberil.

r The. contents ofth'eireaction chamber- 3 are then mixed thoroughly by'shaking orfthef like, to release substantially! all of the blo odcarried gas as a vapor; of which carbon monoxide released'from' carbon-haemoglobin is taken herein as being' -representative; ,within the interiorlof the reaction chamber 3. At'this-stage'of'the development; substantially all of the gas carrying blood sample is posititirled iwithiir thef'reaction chamber 3 and is thoroughly rr'iixedwith' those reagents wliieli areto act upon the blood ample in relea'sing its'ga'seous conte'nt therefrom. With- 7 thi shakenlreaction chamber 3; the crackedtglass; by a mechanieal scrubbing actiomiassilstsridpromoting the reaction betw'een; the.-:blool l-;and;the; reagents: present, in

- 'Tdefprevioiislyfl evacuated tube'16, the reaction chamber-f3. The capsule ,7, andan other c'apsuleswhich,

: untillthe P i n a becne 'xpo d hours meme.

needle tip 2, to pass along the channel of the needle 1 and to displace any blood within the needle 1 and cause it to flow into the reaction chamber 3" where'itis reacted with by the reagents present in causing the liberation of the carbon monoxide gas therefrom.

draws the; vapor content within" the reaction chamber 3 vthrough the colorimetric. tube 15, thereby replacingthe vapor within the reaction chamber 3 with ambientwhich 'entersgthe reaction chamber- 3 through the channel ofithe hypodermic needlel. I 1:

Theoriginal color of the. yellow colorimetric 1G oi-the colorimetric tube 15 matches the yellow' color of;

' the patch- 20, 0f; a patch series numbered20 to, 25,: in;

clusive, shown in Fig. 7. The patch series 21016 inclusiveare shaded from the yellow patch 20 through greens-21,22 23 and 240i increasing blue conteht, to the blue patch 25, The yellowpetcliio, as indicatedin line.

26 thereabove, indicates. zero percentageofcarbon 7 monoxide: inair. The other'color patches il to 25; in

clusive ar ecolor; shades assumed by the celorim'etr ic band 116 of the colorimetric tube -1 inthe presencewithim the reaction chamber; 3v of suflicient quantities. of earb'on monoxide, in air; int registgration with the individual patches" andi'appear' in gin li'ne '2 o thereabove, to cover the-range from300 5, to .lpercentageof carbon monoxide:

111 311 e e e Above the row- 26 inFig. 'lof the drawingappears rows' and columns of patient exposure eifects" from carbon monoxide'in air.- In the first columnall of the squares bear the, legend no eflec lathe secondcolumn; in; orderaf-rom'thebottom, thereare fno appreciableefiects tion of .005 carbon monoxide in atwhich timethe effects are just perceptible? In-thethird columnin order from. bottom for; carbon: mdnoxide concentrations in-air-of 01%, the patient experiences" no appreciable efiects from exposure from oneto three hours,; inclusiyel. In' the fourth hour eifects are.jus t perceptible and when exposed for eight; hours the "patient experiences ,-apre-' ciableefiects.-v ln'the fourth columna-patient exppsed to 0.02% carbon monoxide of air'for one hlour experiences do: appreciable; fiecisi'; wh n he i e pos d' er two'c ,three hours he experiences appreeiabl'ejefiectsl; when he islexposed for fourhoursthe-patientexperiences flIeadaches and nausea andfthe patient exposed'to: 0-.Q2%

carbonmonoxideiimaieeigh eholiie iigi fil g fgl f he continued slow dilation oh the squeeze'bulb condition. In the fifth column a patient exposed to 0.04% carbon monoxide for one hour experiences appreciable effects; for two hours he experiences head aches and nausea; and he is in dangerous condition when he is exposed from three to eight hours to 0.04% carbon monoxide in air. A patient exposed to 0.1% carbon monoxide in air for one hour experiences headaches and nausea; when he is exposed for two hours he is in a dangerous condition; and death results from exposure to 0.1% carbon monoxide in air for three hours and beyond.

The data chart represented in Fig. 7 is derived from the Bureau of Standards, as connected with the equipment shown in Fig. 6. The squeeze bulb 17 has a content of about 60 cc. Within the reaction chamber 3, the cracked glass permeated by bubbling air passing through the blood sample in the presence of the described reagents, provides a scrubbing action which assists in the substantially complete extraction of carbon monoxide from the blood sample. The mixing of the blood sample with the reagents within the reaction chamber 3 is continued for a prescribed period of time, of which 30 seconds may be taken as being illustrative, to insure the complete release of carbon monoxide from the blood. The equipment and the procedures disclosed herein may be used for quantitative determinations of materials other than the described procedure, within the conception of the present invention.

It will be understood that modifications may be made in the equipment disclosed, in the reagents cited and in the manipulations described and in departures from the standard conditions of temperature and pressure contemplated hereby, for particular adaptations and uses without departing from the spirit and the scope of the present invention.

I claim:

,1. A blood gas analyzer for being used with blood sampling equipment, the analyzer comprising in combination a hollow hypodermic needle, a flexible plastic walled reaction chamber having a neck portion supporting at one end the needle, and a hollow and evacuated frangible capsule provided with one end that is rupturable by the proper deflection of the reaction chamber neck portion and that is mounted in the reaction chamber neck portion in connection with the supported end of the needle and in support of the entire capsule within the chamber and which capsule may be ruptured through the chamber Wall for opening the capsule interior to the inside of the reaction chamber for the making of quantitative determinations of the gas content of blood samples drawn through the needle in an amount determined by the degree of evacuation that exists inside of the evacuated capsule into the inside of the reaction chamber of the analyzer.

'2. The analyzer defined in the above claim 1 inclusive of a second hollow and frangible capsule with a reagent contained by the second capsule within the reaction chamber and adapted for being released by the rupture of the second capsule by its manipulation through the flexible wall of the reaction chamber in accomplishing the release of an absorbed gas from a blood sample which may be contained within the reaction chamber.

3. A hypodermic syringe comprising the combination of a flexible walled reaction chamber having a neck portion, a hypodermic needle supported at one end by the neck portion of the reaction chamber, a first capsule of tubular glass that is evacuated and that has one frangible end supported in the same reaction chamber neck portion that supports the needle and the body of the glass first capsule positioned within the reaction chamber and the evacuated first tubular glass capsule being adapted for being opened by the deformation for the reaction chamber neck portion and for drawing through the hypodermic needle a predetermined volume of blood to within the first capsule in the reaction chamber, a second capsule action with the blood within the reaction chamber upon the rupture of both the first and the second capsules through the flexible wall of the reaction chamber and the reagent reacting with a gas content of the blood sample for causing its release in the vapor phase within the reaction chamber.

4. A hypodermic syringe comprising the combination of a hypodermic needle, a flexible walled reaction chamber having a neck portion supporting the hypodermic needle, a plurality of capsules within the reaction chamher and frangible by finger pressure through the walls of the reaction chamber for the purpose of rupturing the capsules and one of the capsules being evacuated and the evacuated capsule having a frangible end supported by the reaction chamber neck portion and that capsule imparting its evacuated condition to the interior of the needle upon the rupture of the neck of the evacuated capsule and the evacuated capsule being adapted for introducing a predetermined quantity of blood sample within the reaction chamber under ambient standard conditions of temperature and pressure, and a hypodermic needle protecting cap containing a hypodermic needle sterilizing material and a swab for the mechanical application of the sterilizing material to the hypodermic needle.

5. A hypodermic needle assembly consisting of the in-' tercombination of a reaction chamber having a tough flexible wall portion which is deformable by finger pressure and continuing in a neck portion, a hollow needle with a sharpened'flrst end projecting from the reaction chamber and the needle having a second end mounted in and supported by the reaction chamber neck portion and the needle mounted and available for opening into the interior of the reaction chamber, an evacuated capsule positioned within the reaction chamber with one attached end mounted in the reaction chamber neck por tion and rupturable from external pressure applied thereto for the purpose of applying its evacuated condition to the attached end of the hollow needle on the rupturing of the evacuated capsule, a reagent containing capsule within the reaction chamber and adapted for being ruptured through the wall thereof for the purpose of releasing the contents of the reagent containing capsule into the interior of the reaction chamber to mix with the contents of the evacuated capsule on the rupture thereof, a hypodermic needle cap protectively housing the distal end of the hypodermic needle and engaging in sealing relation with a portion of the reaction chamber, a swab within the hypodermic needle protective cap, and an antiseptic within the hypodermic needle protecting cap for the purpose of sterilizing the needle.

6. A hypodermic needle assembly for making approximations of carbon monoxide in carboxy-haemoglobin of a blood sample comprising the combination of a hypodermic needle, a hollow flexible reaction chamber with a deformable neck and wall portions of which the neck portion supports an end of the hypodermic needle, an evacuated capsule within the reaction chamber and with one frangible end connected into the supported end of the hollow hypodermic needle such that the frangible end is adapted for being ruptured by finger manipulations from the outside of the reaction chamber for the purpose of drawing a predetermined quantity of blood sample into the reaction chamber under standard conditions of temperature and pressure, a hypodermic needle protecting and sterilizing cap for receiving the hypodermic needle within the cap in removable sealing relation with the reaction chamber, a closure cap having a tear seal closing the reaction chamber at the end remote from the hypodermic needle and the tear seal of which closure cap being adapted for being perforated by a commercially available carbon monoxide colorimetric tube adapted for being opened at both ends and for indicating quantitatively the carbon monoxide content of the blood sampl t e re t o hamb 1 pm thewi dr'awal of: the vaporwithin the reaction chaniber through the colo im tu -s ,7 a; 7;- yp c ee as e b y i 7: them k s, of carbon'monoxicle determinations in carbon-haemoglobin Qf' b oo amp e c p in e .cqmb ti no a low hypodermic needle, a hollow and flexibl'e reaction 7 chamber Provided with a neck portionthat gripsa proximalend; of the hypodermic needle, an evacuated firsgcapsule; supported within; the reaction-chamber by the reaction chamber neck portion' and the v evacuated capsule terminating. .atitsjsupported endin ai frangible tip which 7 ex n ufici y n h a ta hed e do the hyp -l dermie needle, to ,cause the frangible tip to rupture onthe lateral displacement of the portion of the evacuated capsulcavvithin the: reaction chamber; a .thin walled glass second capsule; containing lOQ-mi1ligrrns of powdered i D -5mm er y n ef nd Po itio d; wi hi h sre I action chamber,- a capsule c ntaining SO n iilligrarns ofricit i c and 0 m i mi odi m c a ea d .10;

7 millig s' lp w md s n n nt i 3V r ps Q nr-ylic alcoholand from 1. /1 d 2- cubic'centimeters of; water and being positioned within the reaction chamber such that on the combination ofgthe contents of thereaction chamber-with a' sample of. carboxyehaemoglobin blood the combination will produce a color which is indicative quantitatively of the carbon-monoxide content of the bloodsample, 1

s 8'. The.asse1 nbly defined theabove 7 wherein, the evacuated capsule, rather than the third capsule contains the three drops of caprylicia lcohol for Emmi-- mizing the foaming of bloodentering thereactioncharm 9. The assembly definedlinthe above wherein the interiors of the capsules aresubstantially dry and the water is positioned inside of the reaction chamber and outside of the capsules tominimizeidamage by freezing. 10. A syrin ge comprising a hollow steel hypodermic 7 mg frangible lcapsule means within the reaction chamber needle sharpened at an unattached end forskin evqini p n a i a d having a z tta zw e d f r n ed e enipulafiom ai ol a slsd rm e r t on hamber made of a ou h d flesib wl c and t re ct o chamber having at one end a flexible neclgportion ,in

which the attached, end of the needle is mounted in a rested and block communicationwith the interiorofi the reaction chamber and at the end; of; the reaction chamber remote fron rthe needle mounting neclc portion the reaction chamber I is provided with a thin section seal through which access into the interior of the reaction chamber is available, an evacuated capsule provided with a thin and frangible neck portion making as lip fit neckof thereaction chamber and penetrating into the attached base of the needle and the reaction lcharnber neck portion supporting the, evacuated capsule which xt ds ane fl e i i-e the" e iw mbs W1 that on a; sufficient deformation of the reaction'ch'arn;

ber neclcpoiftion the interior of the evacuatedcapsulejs caused to beapplied to the needle, and ,reagent contain;

and rupturable through thechanliber wall.

References c ted in the mes es patent UNITED STATES PATENTS 

